If you got lots of losses, mark-to-market accounting is the way to go, but first you have to meet the IRS requirements for full time trader and make that election early. Best to consult a trader tax specialist.

This is a little incident I like to post here FYI
I will like to make this as simple as possible from first hand experience with the IRS audit.
First I had some large loses in 2002 and in 2003 deducted the loss I carry over to 2004 and then to 2005...
Now in 2006 in November I was called in for a audit for the 2004 year and I had to prove were the amount of losses came from um on other deductions.
Now I have a company checking account and use that to transfer money to the broker with full disclosure as to how I was using company's funds.
well I made the appointment and provide it the Prof, the question the auditors boss was asking Y the trading losses were deducted from the company's tax returns and Y the CPA did not make a separate company or a distinction as to the moneys allocated for trading but that did nut go any further.
Well I call the auditor two times to see what is taking so long for to grant me another appointment and to date I have not heard from them.
Now the IRS so far did not make a fuss over the way the trading activity was handled in the tax returns if I'm called in I will post again.